Synthesis and Evaluation of pH and Thermosensitive Pectin-Based Superabsorbent Hydrogel for Oral Drug Delivery Systems

Therapeutic efficacy of Strobilanthes urticifolia-infused pectin/polyacrylic acid hydrogel for targeted hepatorenal fibrosis mitigation: A multifaceted biomaterial approach

Pectin/polyacrylic acid (PPAA) hydrogel is a unique and versatile biomaterial with applications in drug delivery, wound healing, tissue engineering, and agriculture, owing to its tailored properties and multifunctional attributes. This study aims to harness the therapeutic potential of Strobilanthes urticifolia extract within a PPAA hydrogel matrix to attenuate liver and kidney fibrosis through targeted and sustained delivery of biologically active substances. PPAA hydrogel was prepared by free radical polymerization, followed by its porosity and swelling determination. The results depicted the porous nature of PPAA hydrogel and improved swelling properties at pH 7.4, confirming its drug delivery promise. The polyphenolic-enriched S. urticifolia extracts of leaf and flower were loaded onto PPAA hydrogel, and the loading efficiency was 87% (leaf) and 62.5% (flower). Moreover, slow-release studies showed controlled and prolonged release of polyphenols for 7 days. The polyphenolic-enriched hydrogel's microstructure was characterized using SEM, FTIR, and thermogravimetric analysis (TGA). SEM results revealed a highly porous structure of polyphenol enriched PPAA hydrogel, while FTIR analysis confirmed the presence of functional groups such as OH group of carboxylic acid, aliphatic CH2 stretching due to acrylic acid grafting with pectin, CO stretching due to acid linkage with pectin, CH of aromatic ring, and CH of carboxylate salt in PPAA hydrogel. TGA of PPAA hydrogel showed its stability up to 488°C. Additionally, the S. urticifolia extract loaded PPAA hydrogel displayed significant antibacterial properties and minimum inhibitory concentrations against both Gram-positive and Gram-negative bacteria. In vivo studies carried out on rats demonstrated that polyphenolic enriched PPAA hydrogel significantly attenuates liver and kidney fibrosis. Therefore, it is concluded from the present study that loading of polyphenolic enriched extract from leaves and flower of S. urticifolia enhanced the biomedical applications of PPAA hydrogel. RESEARCH HIGHLIGHTS: The PPAA hydrogel developed in this study exhibits a highly porous structure and improved swelling properties at physiological pH (7.4), making it an excellent candidate for drug delivery systems. S. urticifolia extracts, rich in polyphenols, were successfully incorporated into the PPAA hydrogel with high loading efficiencies of 87% for leaf and 62.5% for flower extracts. Loading of polyphenolic enriched extracts of S. urticifolia onto PPAA enhanced its biological activities such as antibacterial, hepatoprotective, and reno-protective activities as depicted by in vitro and in vivo studies.

Magnetic nanocomposite through coating mannose-functionalized metal-organic framework with biopolymeric pectin hydrogel beads: A potential targeted anticancer oral delivery system

This study designed magnetic nanocomposite hydrogel beads for a potential targeted anticancer oral delivery system. To end this, nanohybrids of Fe3O4/MIL-88(Fe) (FM) were synthesized through in-situ method by the treatment of terephthalic acid (TPA) and (Fe(NO3)3·9H2O) in the presence of Fe3O4 nanoparticles. They were then modified with mannose sugar as an anticancer receptor to achieve a targeted drug delivery system. After loading methotrexate (MTX), they were coated with pH-sensitive pectin hydrogel beads in the presence of a calcium chloride crosslinker for possible transferring the nanohybrids to the intestine through the acidic environment of the digestive system. The results of different analysis techniques showed that the materials were properly synthesized, coated, and loaded. The designed magnetic nanocomposite hydrogel beads showed pH-sensitive swelling and drug release rate, protecting MTX from the acidic environment of the stomach. MTT test revealed a good cytotoxicity toward colon cancer HT29 cell lines. Remarkably, the functionalization of MTX-loaded FM nanohybrids with mannose (MTX-MFM) enhanced their anticancer properties up to about 20 %. The results recommended that the prepared novel magnetic nanocomposite hydrogel beads have a good potential to be used as a targeted anticancer oral delivery system.

Self-assembled/composited lignin colloids utilizing for therapy, cosmetics and emulsification

Lignin, the most abundant source of renewable aromatic compounds on the planet, is attracting more scholarly attention due to its possibility of replacing petroleum-based chemicals and products. However, it remains underutilized because of the heterogeneity of its multi-level structure that prevents homogenization and standardization of derived products. The key to solving these problems lies in finding a general preparation method to achieve the integrated utilization of lignin molecules at all levels. The assembly-mediated granulation methods provide a significant means for the integrated value-added utilization of lignin, and for biomass productization applications, it is significant to understand the molecular mechanisms of lignin nano-colloids (LNCs) formation thus accurately guiding their functionalization. Therefore, a thorough understanding of the assembly morphology and behavior of lignin in different solutions towards colloids is of great scientific importance. In this minireview, we focus on the assembly behavior of lignin in different solvents, specifically in mono-solvent and multi-solvent, and in particular, we review various methods for preparing lignin composite colloids and concentrate on the applications in therapy, cosmetics and emulsification, which are important for guiding the preparation and efficient utilization of LNCs.

Amphiphilic Alkylated Pectin Hydrogels for Enhanced Topical Delivery of Fusidic Acid: Formulation and In Vitro Investigation

Hydrogels constructed of amphiphilically modified polysaccharides have attracted a lot of interest because of their potential to augment drug diffusion over the skin. This research describes the synthesis of amphiphilic alkylated pectin via glycidyl tert-butyl ether modification (alkylation degree 15.7%), which was characterized using spectroscopic and thermal analysis techniques and then formulated into hydrogels for the study of their potential in regulating fusidic acid diffusion topically. The hydrogels were formulated by the ionic interaction of negatively charged pectin and positively charged crosslinker CaCl2, with a reported fusidic acid loading degree of 93–95%. Hydrogels made of alkylated pectin showed a lower swelling percentage than that of native pectin, resulting in a slower fusidic acid release. The influence of pH on the swelling percentage and drug release was also investigated, with results revealing that greater pH enhanced swelling percentage and drug release. The in vitro interactions with HaCaT cells revealed negligible cytotoxicity under application-relevant settings. Utilizing Franz diffusion cells, the alkylated pectin hydrogels caused fusidic acid to penetrate the Strat-M® membrane at a 1.5-fold higher rate than the native pectin hydrogels. Overall, the in vitro results showed that alkylated pectin hydrogels have a lot of promise for topical distribution, which needs further investigation.

Stimulus-Responsive Nanoconjugates Derived from Phytoglycogen Nanoparticles

Plant-derived phytoglycogen nanoparticles (PhG NPs) have the advantages of size uniformity, dispersibility in water, excellent lubrication properties, and lack of cytotoxicity; however, their chemical functionalization may lead to loss of NP structural integrity. Here, we report a straightforward approach to the generation of PhG NP conjugates with biologically active molecules. Hydrogen bonding of bovine serum albumin with electroneutral PhG NPs endows them with additional ligand binding affinity and enables the electrostatically governed attachment of methotrexate (MTX), a therapeutic agent commonly used in the treatment of cancer and arthritis diseases, to the protein-capped NPs. We showed stimuli-responsive release of MTX from the PhG-based nanoconjugates under physiological cues such as temperature and ionic strength. The results of this study stimulate future exploration of biomedical applications of nanoconjugates of PhG NPs.

Superabsorbent polymers: A state-of-art review on their classification, synthesis, physicochemical properties, and applications

Superabsorbent polymers (SAP) and modified natural polymer hydrogels are widely and increasingly used in agriculture, health care textiles, effluent treatment, drug delivery, tissue engineering, civil concrete structure, etc. However, not many comprehensive reviews are available on this class of novel polymers. A review covering all the viable applications of SAP will be highly useful for researchers, industry persons, and medical, healthcare, and agricultural purposes. Hence, an attempt has been made to review SAPs with reference to their classifications, synthesis, modification by crosslinking, and physicochemical characterization such as morphology, swellability, thermal and mechanical properties, lifetime prediction, thermodynamics of swelling, absorption, release and transport kinetics, quantification of hydrophilic groups, etc. Besides, the possible methods of fine-tuning their structures for improving their absorption capacity, fast absorption kinetics, mechanical strength, controlled release features, etc. were also addressed to widen their uses. This review has also highlighted the biodegradability, commercial viability and market potential of SAPs, SAP composites, the feasibility of using biomass as raw materials for SAP production, etc. The challenges and future prospects of SAP, their safety, and environmental issues are also discussed.

Biosourced Polysaccharide-Based Superabsorbents

In the last decades, many studies have been conducted on new materials to meet a growing industrial demand and to move scientific research forward. Superabsorbents are good examples of materials that have generated special attention in many fields for their ability to absorb and retain water up to 1000 times of their dry weight. They found many applications in hygiene products and other products, for a fast growing market of USD 9.58 Billion in 2019. Most of them are composed of synthetic polymers, which are often not environmentally friendly. Therefore, natural superabsorbents and particularly those based on polysaccharides have received a recent increased interest for their biodegradability, biocompatibility, and renewability. This review focuses on polysaccharide-based superabsorbents, on their properties, synthesis methods, and characterization. Their potential applications in many fields, such as biomedical and hygiene, agriculture, water treatment, and the building sector, are also reported with an interest in products already marketed.

Recent Advances in Edible Polymer Based Hydrogels as a Sustainable Alternative to Conventional Polymers

The over increasing demand of eco-friendly materials to counter various problems, such as environmental issues, economics, sustainability, biodegradability, and biocompatibility, open up new fields of research highly focusing on nature-based products. Edible polymer based materials mainly consisting of polysaccharides, proteins, and lipids could be a prospective contender to handle such problems. Hydrogels based on edible polymer offer many valuable properties compared to their synthetic counterparts. Edible polymers can contribute to the reduction of environmental contamination, advance recyclability, provide sustainability, and thereby increase its applicability along with providing environmentally benign products. This review is highly emphasizing on toward the development of hydrogels from edible polymer, their classification, properties, chemical modification, and their potential applications. The application of edible polymer hydrogels covers many areas including the food industry, agricultural applications, drug delivery to tissue engineering in the biomedical field and provide more safe and attractive products in the pharmaceutical, agricultural, and environmental fields, etc.

Crack Mitigation in Concrete: Superabsorbent Polymers as Key to Success?

Cracking is a major concern in building applications. Cracks may arise from shrinkage, freeze/thawing and/or structural stresses, amongst others. Several solutions can be found but superabsorbent polymers (SAPs) seem to be interesting to counteract these problems. At an early age, the absorbed water by the SAPs may be used to mitigate autogenous and plastic shrinkage. The formed macro pores may increase the freeze/thaw resistance. The swelling upon water ingress may seal a crack from intruding fluids and may regain the overall water-tightness. The latter water may promote autogenous healing. The use of superabsorbent polymers is thus very interesting. This review paper summarizes the current research and gives a critical note towards the use of superabsorbent polymers in cementitious materials.

Modified chitosan for the collection of reactive blue 4, arsenic and mercury from aqueous media

In the present investigation a series of modified chitosan as adsorbents were synthesized free radically at 70 °C using acryloylated chitosan (AC-chitosan) as macromer, 2-acrylamido-2-methyl-1-propansulfonic acid (AMPS), 2-(diethylamino) ethylmethacrylate (DAEMA) as co-monomers and N,N'-methylene bisacrylamide (N-MBA) as a crosslinker for using as adsorbents in effluent remediation. Their structures ((1)H and (13)C NMR), thermal stability (TG/DTG), surface morphology (SEM), reactive blue 4 (RB4), toxic metals such as arsenic (AsO(2-)) and mercury (Hg(2+)) uptake, swellability and reusability were evaluated. The adsorption of RB4 (701 mg/g), and the uptake of AsO(2-) (551 mg/g) and Hg(2+) (455 mg/g) showed Langmuir isotherm behavior with pseudo-first-order kinetics. The diffusion of water, RB4, AsO(2-) and Hg(2+) into the matrix followed non-Fickian mechanism. The evaluated changes in Gibbs free energy (ΔG°), entropy (ΔS°) and enthalpy (ΔH°) for adsorption indicated that the process was exothermic.

Removal of heavy metal ions from wastewater by a novel HEA/AMPS copolymer hydrogel: preparation, characterization, and mechanism

This study aims to synthesize 2-hydroxyethyl acrylate (HEA) and 2-acrylamido-2-methylpropane sulfonic (AMPS) acid-based hydrogels by gamma radiation and to investigate their swelling behavior and heavy metal ion adsorption capabilities. The copolymer hydrogels prepared were characterized via scanning electron microscopy, Fourier transformed infrared spectra, thermal gravimetric analysis, and X-ray photoelectron spectroscopy. The research showed that the copolymer hydrogel was beneficial for permeation due to its porous structure. In addition, the experimental group A-2-d [70 % water volume ratio and (n (AMPS)/n (HEA)) =1:1] was an optimal adsorbent. The optimal pH was 6.0 and the optimal temperature was 15 °C. Pb(2+), Cd(2+), Cu(2+), and Fe(3)+ achieved adsorption equilibriums within 24 h, whereas Cr(3+) reached equilibrium in 5 h. Pb(2)+, Cd(2+), Cr(3+), and Fe(3+) maximum load capacity was 1,000 mg L(-1), whereas the Cu(2+) maximum capacity was 500 mg L(-1). The priority order in the multicomponent adsorption was Cr(3+)>Fe(3+)>Cu(2+)>Cd(2+)>Pb(2+). The adsorption process of the HEA/AMPS copolymer hydrogel for the heavy metal ions was mainly due to chemisorption, and was only partly due to physisorption, according to the pseudo-second-order equation and Langmuir adsorption isotherm analyses. The HEA/AMPS copolymer hydrogel was confirmed to be an effective adsorbent for heavy metal ion adsorption.

Drug delivery applications for superporous hydrogels

INTRODUCTION

Considerable advances have been made to hydrogels with the development of faster swelling superporous hydrogels (SPHs). These new-generation hydrogels have large numbers of interconnected pores, giving them the capacity to absorb large amounts of water at an accelerated rate. This gives SPHs the ability to be used in a variety of novel drug delivery applications, such as gastric retention and peroral intestinal delivery of proteins and peptides.

AREAS COVERED

This review focuses on the applications of SPHs for drug transport and targeted drug therapies, as well as the characteristics and historical advancements made to SPH synthesis as it pertains to drug delivery. Manufacturing considerations and challenges that must be overcome are also discussed, such as scale-up, biocompatibility and safety.

EXPERT OPINION

Modern SPHs have high swelling and high mechanical strength making them suitable for many diverse pharmaceutical and biomedical applications. However, demonstrative preclinical animal studies still need to be confirmed in human trials, to further address safety issues and confirm therapeutic success when using SPHs as platforms for drug delivery. The focus of forthcoming applications of SPHs is likely to be in the area of oral site-specific delivery and regenerative medicine.

The removal of heavy metal ions from aqueous solutions by novel pH-sensitive hydrogels

Novel non-ionic hydrogels were synthesized by radical homopolymerization of N-vinyl-2-pyrrolidone (VP) or by radical copolymerization of VP with methylacrylate (MA). A macroinimer (MIM) was used as a crosslinker and initiator, as well. The percentage of mass swelling ratios (S(M)), the molecular weight between crosslinks (M(c)) and Young's modulus of the hydrogels were investigated. The hydrogels were used as binding materials for different heavy metal ions such as Cu(2+), Cd(2+), Ni(2+) and Zn(2+) under varying conditions. The binding capability of the hydrogels toward the metal ions decreases in the following order: Cu(2+)>Ni(2+)>Zn(2+)>Cd(2+).